1)
Who was Shovi ben Nachash?
1.
Rashi citing Shochar Tov 3:3: It is Chanun ban Nachash mentioned above (10:2). 1
2.
Radak: He was a Yisrael who lived in Rabas Bnei Amon after David conquered it.
1
Radak: This Drashah is difficult. Why would David keep him alive? David did Mishpatim (killed) the entire nation in Rabah and in all cities of Amon, and Chanun shamed David's Sheluchim! Perhaps he converted, and David left him alive.
2)
Why was he called ha'Gil'adi mi'Roglim?